Mine prop assembly



March 2 1966 HANS-THEODOR GRISEBACH 3,241,323

MINE PROP ASSEMBLY Filed Aug. 7, 1961 2 Sheets-Sheet l March 22, 1966HANS-THEODOR GRISEBACH MINE PROP ASSEMBLY Filed Aug. '7 1961 2Sheets-Sheet 2 Fig.3

WIIIIIIIIIIII United States 3,241,323 MINE PROP ASSEMBLY Hans-TheodorGrisebach, Lunen-Galmen, Germany, assignor to Gewerkschaft EisenhiitteWestfalia, Wethmar, near Lumen, Westphalia, Germany Fiied Aug. 7, 1961,Ser. No. 1l3,732 Claims priority, application Germany, Aug. l3, 1969, G3%,281 11 Claims. (Ci. 61-45) This invention relates to mining apparatusand more particularly to a device for use in supporting mine roofs.

The system of mining in which this invention is particularly useful isemployed in extracting coal underground or any similar material whichlies in seams. To extract the coal, the face of the seam is exposed on along wall. Usually in a relatively low room, a cutter travels along theface of the seam plowing the coal from the face onto a conveyor. Theroof of the room behind the cutter and conveyor is supported by propsarranged in a gang of units, each unit generally consisting of two pairsof columns or props which are hydraulically extended to the roof.

The pairs of columns are so arranged that while one supports the roof ofthe other pair can be moved for ward as the cutting proceeds and then asthe one which has been advanced is raised to support the roof the otherpair of props are loosened and moved up beside the first.

As such units have been arranged heretofore, loosening of one set ofprops from the roof has often had the effect of permitting the roof tosag, thereby causing cracks leading to obvious difiiculties. In somecases where the columns have been equally spaced the attempt has beenmade to correct this condition by enlarging the size of the capscontacting the roof. This has not been successful in many cases becausethe roof surface is not often even to provide good bearing surface.Furthermore, when the caps cover a large area, it is difficult to lowerthem to move them forward. Sometimes the caps have been provided withinterlocking parts so that they slide on one another. Such anarrangement is very awkward as will be understood since the footing forthe columns must move along with the caps, and the pair of columns mustbe kept parallel. Furthermore, if the columns are flexibly mounted withrespect to each other the problem of guiding them while they are beingadvanced is diflicult.

A better arrangement is to provide smaller bearing surfaces for thecolumns at the roof which make better contact with the roof than widecaps, and in accordance with this invention the caps are made relativelysmall and they are placed close together so that when one is moved theother which lay beside it holds up the roof. On account of theunevenness of the floor which has a tendency to tilt the columns out ofposition, special provision is made to assure that the caps will stay inposition close to each other after both have been advanced; Theinvention provides guide means which will enable the columns to pass oneanother without turning out of position. It will be seen that as one setof columns is being advanced the columns which were adjacent willsupport substantially the same area of roof and thus it is not necessarythat the distance advanced be large. Ordinarily it will not be greaterthan about half the distance between the fore and aft columns.

A further feature of the invention is the use of guides for the capswhich guides them not only vertically but horizontally and incombination with the resilient mounting they maintain the adjacent capssubstantially in contact with each other and tend in some cases to tiltthe columns toward each other at the top. Thus, pieces of ice rock fromthe roof will not get caught between the caps.

Another feature of the invention is the flexibility of the footing whichaccommodates itself to unevennesses of the [loor while maintainingparallelism.

It is accordingly an object of the invention to provide a prop unit ofthe type described which is adapted to adequately support the roof ofthe workings, simple to operate and easy to manufacture.

Other objects and advantages of the invention will be in part obviousand in part pointed out hereinafter.

In the drawing in which two embodiments of the invention are shown,

FIG. 1 is a side view of a mine prop constructed in accordance with thepractice of the invention and showing a plurality of units in gangarrangement;

FIG. 2 is a plan section taken along the line 2-2 of FIG. 1;

FIG. 3 is a front view of a modified form of prop unit partly in sectionalong the line 3-3 of FIG. 4; and

FIG. 4 is a horizontal section along the line 44 of FIG. 3.

Referring to the drawing and particularly to FIG. 1 and FIG. 2, thereare illustrated a complete unit and parts of two others arranged in sideby side gang formation, the complete unit being shown at the center. Aunit in this embodiment consists of a set of footings 1t and 12 arrangedparallel to each other. Each footing is provided with a pair of propmeans or columns, collum 14 being at one end of footing 10 and column 16being spaced from column 14 and at the. other end of footing 10.Likewise on footing 12 is mounted a forward column 18 and a rearwardcolumn 20. Each column is tiltably mounted on its footing and isextensible, being hydraulically operated preferably, and has a cap atits top. Thus column 16 has a cap 22 together with column 14 and column13 has a cap 24 together with column 20 in the usual way, which caps arepressed against the roof of the working 26 to support it temporarily.

Footings 10 and 12 are adapted to slide along the fioor with respect toone another and to be maintained in parallelism and for this purposethere is provided a hydraulic cylinder 28 having a piston rod 30.Hydraulic cylinder 28 is joined by resilient straps or flat springmembers 32 to footing 12, and piston rod 30 is likewise joined tofooting 19 by resilient straps or flat spring members 34. Being wide andflat, resilient straps or spring members 32 and 34 allow no lateralmovement but are flexible vertically so that as footings 10 and 12 movewith respect to each other they can conform to unevennesses of the floorboth in an endwise direction and transversely.

To compensate for any transverse tilting of footings it and 12, columns16 and 18 are provided with springs 36 attached to the footings andpressing against the columns so that the caps 22 and 24 tend to bearagainst adjacent caps for purposes explained hereinafter.

Advancing of the column is accomplished in a sort of walking motion, thepower therefor being supplied by hydraulic cylinder 28 and the pistonrod 30. Thus when it is desired to advance columns 14 and 16, the capsof these columns are lowered by the telescoping action of columns 14 andlo, and footing 10 is stepped forward by hydraulic pressure applied topiston rod 30. After being stepped forward a suitable distance, column14 and 16 are extended so that then caps contact roof 26, whereuponsimilar actuation of columns 18 and 20 and power applied to hydrauliccylinder 28 and piston 30 stepsfooting l2 forward. Because of theflexibility of members 32 and 34, footings 1t) and 12 accommodatethemselves to the floor surface.

As has been indicated above the unit described is adapted to be used incombination with similar units as indicated. Thus an additional unitshown at the right (FIG. 1) is provided with columns 16 and 14- and thefooting 1d and an additional unit shown at the left in part is providedwith a footing l2 and columns 18 and 20'. Column 18' has a cap 24' tocontact roof 26 and column 16' has a cap 22' also adapted to engage roof26. Actually, the footing 12 from the spaced apar footing set 10, 12forms a footing pair 12, lid with the correspondingly adjacent footingtil for joint or separate partial support of the mine roof, while thefooting 19 from set 10, 12 forms an analogous footing pair 1 12 with thecorrespondingly adjacent footing 1.2.

In the gang arrangement indicated in FIG. 1 and FIG. 2 the units arearranged to slide in parallelism with respect to each other and for thispurpose the adjacent footings in a respective footing pair are providedwith a tongue and groove coupling which compels them to movehorizontally in parallelism while permitting a degree of flexibility invertical direction. Thus, in the footing pair l2, l, footing 12 isprovided with a longitudinal slot member 38, in which is adapted toslide the tongue 4th of footing Likewise, in the footing pair 12', til,the tongue 42 provided on footing 12 engages the slot member 44 providedon footing it inasmuch as the springs 36 tend to push the variouscolumns away from the center of the set and therefore push the adjacentcolumns in a footing pair toward each other the caps at the tops of thecolumns Will be forced against one another and thus press againstadjacent areas of the roof 26.

Means is provided to prevent interference of the caps as they pass byeach other and to assure that they will assume suitable positionsagainst the roof 26 when they have been stepped forward. Such means isadapted not only to guide the caps into their uppermost positions but intheir retracted positions as well. For this purpose each cap is providedwith a plate 46 extending downwardly and longitudinally and which areadapted to contact each other at all times on adjacent cap-s. Thus whencolumn 16 is retracted its plate 46 slides downwardly with respecet tothe plate 46 on column 18' and in that position as the column is steppedforward it will assume a suitable position for reextension of column 116so that when column 13 is again advanced the interaction of plates 46guide cap 24' into a position such as is shown in FIG. 1 where caps 22and 24 are adjacent and mutually support substantially the same area ofroof.

In FIG. 3 and FIG. 4 is illustrated a prop unit which may be usedindependently, that is to say, unguided by other units although suchother units will be usable in conjunction therewith. In this embodimentpiston rod 54 is carried by footing and the hydraulic cylinder 56 isattached to footing 52 by the spring plate 58. Footings 50 and 52 form afooting pair and the footings are adapted to slide with respect to eachother and in contact with each other. Footing 52 flexibly supports apair of prop means or columns as and 62 adjacent to the pair of columns6 and 66 likewise flexibly supported on footing 52 and adjacent tocolumns as and 62, respectively. Each column 60 and 62 is provided witha cap 68 contiguous to caps 70 supported by columns 64 and 66.

For the purpose of guiding caps 68 and '70 with respect to each otherplates 72 and '74 are provided on caps 68 and 70, respectively, andperform the functions of plates 46 of the previously describedembodiment.

In this instance parallelism of footings 56 and 52 is assured by theirbeing maintained throughout their length in contact with each other bythe flexible plate 58. On account of flexibility of this plate footings5t) and 52 are able to move sufficiently vertically and otherwise toconform to the irregularities of the floor. Footings and 52 are inclinedtoward each other so that caps 68 and 70 remain in contact by means ofoffset feet 76 and 78 i attached to the footings 5i and 52,respectively, and offset therefrom. A relief spring 84 is provided oneach foot 76 hearing against columns 60 and 62 to resiliently press theminto contact at their caps 68 with caps 75 of columns as and 66.

In this embodiment the caps of each unit are adjacent so that the unitmay be used independently of other units or in conjunction therewith.Otherwise the function of the guide plates 72 and 74 has the same effectas the guide plates 46 of the embodiment of FIG. 1 and FIG. 2 whereinthe adjacent columns belong to separate prop units.

Thus by the above construction are accomplished among others the objectshereinbefore referred to.

I claim:

1. Mining prop arrangement which comprises a pair of laterally adjacentfootings, at least one prop means mounted substantially vertically oneach footing adjacent a corresponding prop means on the other footing,each particular footing and said at least one prop means mounted thereonforming a respective prop assembly, advancing means cooperative withsaid footings and connected to at least one said prop assembly toadvance said footings longitudinally with respect to each other, andbiasing means connected to at least one said prop assembly and arrangedfor normally urging the upper end portion of one said prop means on onefooting into slidably guiding abutment with the upper end portion of theother correspondingly adjacent prop means on the other footing.

2. Arrangement according to claim 1 wherein said prop means arehydraulically extensible, said footings being longitudinally slidablyinterconnected by slot guiding means on each footing longitudinally andvertically displaceably cooperating with one another for permittingvertical and longitudinal movement between said footings whilepreventing transverse movement therebetween, said biasing meansincluding spring means interposed between the lower end portions of saidprop means and the respective footing therefor laterally remote fromsaid slot guiding means, and said upper portions being each providedwith a plate means thereof having a lateral sliding surface adjacent andfacing the corresponding sliding surface of the other upper end portionfor maintaining sliding abutment thereat between the correspondinglyadjacent prop means under the urging of said spring means.

3. Arrangement according to claim 1 wherein said prop means arehydraulicaly extensible, said footings being longitudinally slidablyinterconnected by mounted common piston-cylinder means, saidpiston-cylinder means having vertically flexible connecting meansvertically flexible interconnecting said piston-cylinder means to one ofsaid footings for advancing said footings longitudinally with respect toeach other while permitting vertical flexible movement between saidfootings yet preventing transverse movement therebetween, said footingsbeing provided with offset feet laterally outwardly thereof positionedfor normally urging the correspondingly adjacent upper end portions ofsaid prop means toward one another, said biasing means including springmeans loaded between the lower end portion of one of said prop means anda corresponding offset foot, thereat for normally urging the upper endportion of said prop means toward the upper end portion of the othercorrespondingly adjacent prop means, and said upper end portions beingeach provided with a plate means thereon having a lateral slidingsurface adjacent and facing the corresponding sliding surface of theother upper end portion for maintaining sliding abutment thereat betweenthe correspondingly adjacent prop means under the urging of said springmeans and said offset feet.

4. Mining prop arrangement which comprises a plurality of footing setsutilized in gang formation, each set having two spaced footings, atleast one extensible prop means mounted substantially vertically on eachspaced apart footing adjacent a corresponding prop means on thelaterally adjacent footing of the next set whereby to form thereat apair of correspondingly adjacent footings with correspondingly adjacentprop means, advancing means cooperative with said footings to advancethe spaced apart footings of each set longitudinally with respect toeach other and longitudinally with respect to the correspondinglyadjacent footing of the respective footing pair, and biasing meansarranged for normally urging the upper end portion of the prop means oneach spaced apart footing into slidable guiding abutment with the upperend portion of the corresponding prop means on the adjacent footing ofthe next set, which adjacent footing forms therewith a footing pair,

5. Arrangement according to claim 4 wherein said prop means arehydraulically extensible, said advancing means including a commonpiston-cylinder means having vertically flexible interconnecting meansvertically flexibly interconnecting the spaced apart footings of eachset for advancing said footings longitudinally with respect to eachother while permitting vertical flexible movement between said footingsof each set yet preventing transverse movement therebetween, the spacedapart footings of each set being respectively longitudinally slidablyinterconnected by separate slot guiding means on each footinglongitudinally and vertically displaceably cooperating with a separateslot guiding means on the correspondingly adjacent footing of the nextset, which adjacent footing forms therewith a footing pair respectively,for permitting vertical and longitudinal movement between thecorrespondingly adjacent footings of said pairs respectively whilepreventing transverse movement therebetween, said biasing meansincluding spring means operatively interposed between the lower endportions of said prop means and the respective footings therefor in eachset laterally adjacent said common piston-cylinder means, and said upperend portions being each provided with plate means thereon having alateral sliding surface adjacent and facing the corresponding slidingsurface of the upper end portion of the prop means on the adjacentfooting of the next set, which adjacent footing forms therewith afooting pair, for maintaining sliding abutment thereat between suchcorrespondingly adjacent prop means in each pair under the urging ofsaid spring means.

6. Mine prop arrangement adapted to be utilized in gang formation whichcomprises a pair of laterally adjacent footings, a pair of extensibleprop means mounted substantially vertically on each footing respectivelyadjacent a corresponding pair of extensible prop means on the otherfooting, each particular footing and the pair of prop means mountedthereon forming a re spective prop assembly, means cooperative with eachfooting and connected therewith to move said footings longitudinallywith respect to each other, and resilient means connected to at leastone of said assemblies and arranged to press the tops of the prop meanson one of the footings into slidable guiding abutment with the tops ofthe correspondingly adjacent prop means on the other footing.

7. Arrangement according to claim 6 wherein said means cooperative witheach footing include coupling means provided for longitudinal slidingengagement between said footings, said prop means being provided attheir tops with substantially vertically extending top guiding means toguide their tops in their vertical movement past the tops of thecorrespondingly adjacent prop means.

8. Arrangement according to claim 7 wherein said top guiding meansinclude plates affixed to the correspondingly adjacent prop means topsand parallel to each other.

9. Arrangement according to claim 7 wherein said means cooperative witheach footing are arranged to move said footings both longitudinally andparallel with respect to each other and include resilient strapvertically flexible to permit tilting of said footings with respect toeach other.

10. Arrangement according to claim 9 wherein Iesilient link means areprovided which are attached to said footings to pretilt adjacent propmeans toward each other, and said coupling means are defined by a slideguide on each footing operatively engaging the slide guide on theadjacent footing and permitting vertical movement between said adjacentfootings.

11. Arrangement according to claim 7 wherein said prop means aretiltably mounted on said footings and leaf springs mounted on saidfootings press adjacent prop means into slidable guide abutment witheach other.

References Cited by the Examiner FOREIGN PATENTS 565,918 4/1958 Belgium.(corresponding English language, British Patent 885,645)

1,164,448 5/1958 France. (corresponding English language, British Patent850,170)

810,296 3/ 1959 Great Britain. 831,275 3/1960 Great Britain.

OTHER REFERENCES Wiemann, German printed application No. 1,090,159,October 1960.

CHARLES E. OCONNELL, Primary Examiner.

JACOB L. NACKENOFF, JACOB SHAPIRO, EARL J.

WITMER, Examiners.

1. MINING PROP ARRANGEMENT WHICH COMPRISES A PAIR OF LATERALLY ADJACENTFOOTINGS, AT LEAST ONE PROP MEANS MOUNTED SUBSTANTIALLY VERTICALLY ONEACH FOOTING ADJACENT A CORRESPONDING PROP MEANS ON THE OTHER FOOTING,EACH PARTICULR FOOTING AND SAID AT LEAST ONE PROP MEANS MOUNTED THEREONFORMING A RESPECTIVE PROP ASSEMBLY, ADVANCING MEANS COOPERATIVE WITHSAID FOOTINGS AND CONNECTED TO AT LEAST ONE SAID PROP ASSEMBLY TOADVANCE SAID FOOTINGS LONGITUDINALLY WITH RESPECT TO EACH OTHER, SAIDBIASING MEANS CONNECTED TO AT LEAST ONE SAID PROP ASSEMBLY AND ARRANGEDFOR NORMALLY URGING THE UPPER END PORTION OF ONE SAID PROP MEANS ON ONEFOOTING INTO SLIDABLY GUIDING ABUTMENT WITH THE UPPER END PORTION OF THEOTHER CORRESPONDING ADJACENT PROP MEANS ON THE OTHER FOOTING.